Putrescine uptake by alveolar epithelial cell monolayers exhibiting differing transepithelial electrical resistances

Area of Science:

• Cell Biology
• Respiratory Medicine
• Epithelial Physiology

Background:

• Alveolar epithelial cells are critical for lung function.
• Developing in vitro models that mimic in vivo alveolar epithelium is challenging.
• Transepithelial electrical resistance (TEER) is a common measure of epithelial monolayer integrity.

Purpose of the Study:

• To establish and characterize a rat alveolar type II cell culture model.
• To investigate the relationship between culture conditions, TEER, and cell viability.
• To assess the impact of TEER on the functional capacity of alveolar cell monolayers.

Main Methods:

• Isolation and culture of rat alveolar type II cells on polycarbonate filters.
• Monitoring cell differentiation and monolayer formation over 6 days.
• Measurement of TEER and determination of Vmax and Km for putrescine uptake.

Main Results:

• Cell monolayers predominantly composed of alveolar type II cells de-differentiated to type I-like cells by day 6.
• Seeding density and media significantly influenced TEER, with specific conditions yielding TEER > 1000 omega cm2.
• Higher TEER correlated with greater putrescine uptake capacity, suggesting TEER reflects cell viability.

Conclusions:

• The established cell culture system can produce alveolar monolayers mimicking in vivo characteristics.
• TEER is a valuable indicator of both monolayer integrity and cell viability in alveolar cell cultures.
• Careful selection of culture conditions and interpretation of TEER are essential for reliable in vitro lung research.